VHDL is the ieeE standard hardware description language. It consists of all the features of a conventional programming language plus additional structures required to represent hardware. These programming structures e...
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VHDL is the ieeE standard hardware description language. It consists of all the features of a conventional programming language plus additional structures required to represent hardware. These programming structures enable concurrent execution to be defined and mechanisms to describe the assignment of values to signals after delays. The paper describes a method of automating the design route from VHDL to FPGA. This method employs a VHDL compiler to translate structural VHDL representation into a suitable netlist format and processed by the FPGA software to produce the final personality file. The method enables all design decomposition to be carried out in the VHDL environment and thus totally under the control of the designer.
This paper describes on-going research that is currently being undertaken by the control Theory and Applications Centre, Coventry University, into developing controllers which make use of both model-based and rule-bas...
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This paper describes on-going research that is currently being undertaken by the control Theory and Applications Centre, Coventry University, into developing controllers which make use of both model-based and rule-based techniques. The resulting combined controller are able to make 'better' use of available information on the plant and investigative studies to date indicate that such an approach can provide for adaptivity within a robust controller design framework.
Two software packages are introduced to aid in the task of tuning PID controllers. The first is MASTERTUNE which has been developed to automatically determine the necessary PID parameters by interfacing to existing pl...
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Two software packages are introduced to aid in the task of tuning PID controllers. The first is MASTERTUNE which has been developed to automatically determine the necessary PID parameters by interfacing to existing plant controllers and automatically downloading the values upon completion of the tuning exercise. The second is PROdesign, a novel digital control strategy involving the proportional-integral-plus (PIP) algorithm. It provides a complete design environment allowing the user to implement advanced control strategies where required. For cases where a very long time delay clearly degrades the PI(D) response, it was found that PIP produced excellent response.
The use of model-based approaches is proposed to improve the control performance of an industrial polymerization reactor. This involves the development of a process model using system identification techniques, the si...
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The use of model-based approaches is proposed to improve the control performance of an industrial polymerization reactor. This involves the development of a process model using system identification techniques, the simulation of the plant within the Simulink environment to allow for the design and validation of control strategies. From these studies a Smith Predictor was implemented to significantly improve the polymer viscosity control. A hardware platform is developed to facilitate the implementation of sophisticated algorithms such as recursive least squares, that could not be accommodated on the existing DCS.
Implementing QFD requires a certain amount of adaptation to fit to a particular company and project requirements. It is important for users to recognize the reason for its use and to identify the limitations. The main...
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Implementing QFD requires a certain amount of adaptation to fit to a particular company and project requirements. It is important for users to recognize the reason for its use and to identify the limitations. The main potential barriers to successful implementation of QFD are the difficulty of listening to the voice, misinterpretation of message, constantly changing customer needs and too many customers and needs. To understand how these factors affect a project requires static/dynamic analysis and levels analysis. Tools such as reverse component selection, parametric analysis and synectics can facilitate smooth QFD implementation.
The paper addresses the specific problem of designing nonlinear dynamic optimal controlsystems, where the model employed to compute the optimal solution is different from reality. A mathematical model, which is an es...
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The paper addresses the specific problem of designing nonlinear dynamic optimal controlsystems, where the model employed to compute the optimal solution is different from reality. A mathematical model, which is an essential constituent of a control system design technique, inevitably is an approximation of the real technological process that it represents. These model - reality differences may be introduced deliberately, in order to facilitate the mathematical aspects of the design and analysis, or arise due to uncertainties in knowledge of process mathematical structure and parameters. The challenge to the controldesigner is to achieve a control system that is robust to model uncertainties and to try to obtain a suitable design in spite of model reality differences. An approach known as Integrated System Optimization and Parameter Estimation (ISOPE), inspired by Haimes and Wismer (1972), was developed by Roberts (1979) and Roberts and Williams (1981) for on - line steady - state optimization of industrial processes implemented through adjustment of regulatory controller set-points. The method is iterative in nature using repeated solutions of optimization and estimation of parameters within the model used for calculating the optimum. An important property of the ISOPE technique is that the iterations converge to the correct real optimum in spite of the model-reality differences. This paper describes recent research (Roberts, 1993) on the extension of the ISOPE principle to develop an iterative procedure for solving dynamic optimal control problems which specifically takes in to account that the model used in the computations is different, in structure and parameters, from reality. The work is a further development of Dynamic Integrated System Optimization and Parameter Estimation, DISOPE, first introduced by Roberts (1992), in which the convergence behaviour is improved through convexification, and an implementable algorithm based on a linear model and quadratic
A canard-controlled missile airframe configuration with a twist-and-steer (or polar) control system affords economies in design and kinematic performance but at present does not permit a direct analytical solution for...
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A canard-controlled missile airframe configuration with a twist-and-steer (or polar) control system affords economies in design and kinematic performance but at present does not permit a direct analytical solution for the optimum guidance and roll control autopilot laws. The development of a stable roll loop of adequate bandwidth and response is fundamental in a twist-and-steer missile. Whilst the application of modern control theory has been successfully applied to the design of aileron-constrained time-invariant cases, its extension to the nonlinear case requires further development. Roll loop design is commonly carried out using frequency-domain methods coupled with detailed mathematical modelling and digital simulation. The use of commercially available control system design programs facilitates loop design and sensitivity studies across the operating envelope. Describing function techniques may be used to investigate limit cycle stability etc. The paper discusses the aerodynamics and the computer-aided design.< >
In this article the author discussed some important testability issues and advised on what disciplines to teach to cover the subject of testing properly. The desired effect is to persuade Universities to introduce the...
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In this article the author discussed some important testability issues and advised on what disciplines to teach to cover the subject of testing properly. The desired effect is to persuade Universities to introduce these down-to-Earth subjects and work with Industry to convert Graduates into Professional Engineers.
This conference proceedings contains 6 papers. The main subjects are computer aided engineering in surface mount assembly, automatic surface placement equipment, intelligent vision systems, surface mount technology, m...
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This conference proceedings contains 6 papers. The main subjects are computer aided engineering in surface mount assembly, automatic surface placement equipment, intelligent vision systems, surface mount technology, microelectronics research, design for testability, and automatic assembly systems.
What is meant by the 'Mature' Engineer? In the context of the discussion Digital design for Test: What should be taught and Why? , there are two kinds of 'maturity'. One is the freshly graduated engine...
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What is meant by the 'Mature' Engineer? In the context of the discussion Digital design for Test: What should be taught and Why? , there are two kinds of 'maturity'. One is the freshly graduated engineer who enters Industry full of his new knowledge of High Technology, and assumes he has been taught all there is to know about the subject. The other is the Engineer who perhaps graduated some years ago, was formally taught Digital Electronics, has practised his craft for some time with some success, but has developed 'bad habits' and certainly has never been taught design for testability formally. The aim of this paper is to address the problems of both these areas, and to identify the effect these two can have on the end product of their designs, and to suggest some ways of getting the 'design for testability' message across at an early stage in their development, with consequent benefits to all.
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